Transcript for:
Glaucoma

hey everyone it's sarah with registerednessrn.com and in this video we're going to talk about glaucoma and as always whenever you get done watching this youtube lecture you can access the free quiz that will test you on this condition so let's get started glaucoma is a set of eye diseases that is caused by increased intraocular pressure and whenever this happens it results in optic nerve damage so what does our optic nerve do well this nerve helps transmit information that we see with our eyes to our brains so it plays a huge role in giving us our vision so if this nerve becomes damaged the person is going to have vision loss that can eventually lead to permanent blindness for instance if this patient had ankle glaucoma over time eventually they will notice that they're losing their peripheral vision which is going to give them like tunnel vision and if they don't get this treated where they're getting their interocular pressure lowered it can eventually lead to permanent blindness so in this lecture we're going to talk about two types of glaucoma the first type we're going to talk about is called open angle glaucoma and this type is the most common form of glaucoma now the thing you want to remember about this type is that its signs and symptoms are very subtle the patient's not going to really know that they have this type of glaucoma until the disease has really advanced so we refer to this type as the silent type the next type we're going to talk about is called angle closure glaucoma now you may also hear this referred to as narrow angle glaucoma or closed angle glaucoma all those terms refer to this type of glaucoma now this type of glaucoma is very rare and its signs and symptoms the patient is definitely going to notice them and whenever the patient has this type of glaucoma it requires immediate emergency treatment so as a nurse it's very essential that you know the differences between the signs and symptoms with open angle and ankle closure glaucoma now with all types of glaucoma you really want to stress to the patient that early detection is key because this disease can be detected on an eye exam that checks the intraocular pressure a little bit later we're going to talk about that specific exam so first let's talk about the pathophysiology of glaucoma and to help us truly understand this disease process we have to identify the key players that play a role in the pathophysiology so our key players are the intraocular pressure the iop and the aqueous humor so first let's talk about iop what is this well to help us understand that let's take that word apart intra means within and ocular means i so when we put that together we get the fluid pressure within the eye and the fluid that we're specifically talking about is the aqueous humor so intraocular pressure is calculated by the production rate and the drainage rate of this aqueous humor now aqueous humor is produced in the eye specifically by the ciliary body and it drains out through the eye and it's going to go through the trabecular meshwork into like the drainage canals so if your production rate and your drainage rate are not equal you're going to get increased interocular pressure but how in the world do we know a patient's iop well it can be detected through an eye exam and they can use a device called a tonometer and this device will tell us what the patient's iop is now generally a normal iop in most people is about 10 to 21 millimeters of mercury so now let's talk about aqueous humor so we have established that this fluid helps maintain our iop but let's talk about how it really flows through this eye and really compare that to open and angle closure glaucoma so here we have our eye and the view of this eye is if you were looking over someone and you took their eyeball and you just cut it in half and you were just looking at it so this is the view of the eye that we're looking at and here in the drawing we have in red this is the ciliary body and that produces again the aqueous humor we have the lens we have in purple this represents the flow path of the aqueous humor and then here in black we have the pupil opening and then the colored area in green is the iris which is the color part of the eye so our person has green eyes and then we have the cornea which is this area here in black and then we have the trabecular meshwork and schlemm's canal and that's how the aqueous humor is going to leave this part of the eye so let's talk about how it flows normally so the ciliary body produces the aqueous humor and it's going to go through the posterior chamber of the eye and this is found between the iris and the lens then this aqueous humor is going to go through the pupil opening and it's going to enter into the anterior chamber of the eye which is found with the cornea and the iris then the aqueous humerus should normally go down and we're hitting the drainage angles of the eye and i want you to remember drainage angle because that is really the key concept in understanding closed angle or angle closure glaucoma versus open angle glaucoma so it's going to go down through these drainage angles and it's going to hit the trabecular meshwork okay it's mesh work so this trabecular mesh work is like a strainer area so the fluid is going to go down through there and then it's going to go into schwim's canal and then it's going to hit the episcleral veins and that's how it normally should drain out of the eye but to help give you a better illustration let's look at this animation so here is a side view of the eye if you took it and you cut it in half encircled in red is the ciliary body which produces that aqueous humor it's going to flow out through that posterior chamber through the pupillary open through the anterior chamber and then it's going to go down into the trabecular meshwork into the schlemm's canal in the episclerial veins so as you can see this aqueous humor is easily just flowing through the eye but now let's talk about when this aqueous humor doesn't flow too great through the eye and it leads to increased intraocular pressure and we get damage to our optic nerve so first let's talk about open angle glaucoma so i pointed out these drainage angles and the drainage angle of the eye is formed with the cornea and the iris so hence it's a drainage angle it forms an angle between these two structures now in open angle glaucoma this angle is open so the aqueous humor can flow down to where it needs to go into the trabecular meshwork but the problem with open angle is not the drainage angle it's with the trabecular meshwork now i pointed out earlier to think of the mesh work as like a strainer because what happens is as we age this mesh work becomes less flexible it's less permeable it becomes thicker so it will become clogged so this aqueous humor cannot get through the trabecular meshwork and we get increased pressure and as you can see here when the trabecular mesh work is not working the fluid will start to collect in the eye and then you're going to get this increased pressure which is going to put pressure on that optic nerve and can cause vision damage so now let's talk about the signs and symptoms of open angle glaucoma well as i pointed out earlier the signs and symptoms are going to appear very subtly for that patient and whenever they actually notice like that tunnel vision where they're having that loss of that peripheral vision that means this disease has advanced so through early detection we can see some of these other signs and symptoms which lets us know that hey this patient may have open ankle glaucoma so really it's silent in its presentation and you may even hear it referred to as the thief of sight but typically these patients are not going to have pain with this type of glaucoma compared to angle closure glaucoma they're of course going to have increased intraocular pressure most patients will and this will be found through various readings now again how did we determine a patient's iop it was through a tonometer and whenever they look at the patient's drainage angles because you can look at the drainage angles through one of those eye exams they can use a gonioscope to assess that so that can tell us if they have angle closure or open angle and they may have what's called optic disc cupping and this can be assessed with an ophthalmoscope and you can look at the fundus of the eye and you can look at the optic disc to cup ratio and the optic disc is found on the fundus and in the middle of the disc is the optic cup so with chronic open ankle glaucoma the cup will become bigger compared to the disc and here on the right you will see a normal optic nerve notice the cup it's the bright part in the middle is smaller compared to the disc but here on the left the optic cup is a lot bigger compared to the disc now let's talk about angle closure glaucoma so again with these drainage angles we have the cornea and the iris and we have that angle and what's happened is that this angle has narrowed his hints close so this aqueous humor cannot get down into the trabecular meshwork into schlemm's canal and do its thing so we don't have a problem with trabecular's mesh work it's that this angle has closed off and what's going to happen is this aqueous humor is going to build up in on the eye and it's going to really severely hinder this optic nerve now when this type of glaucoma happens it is an emergency it's rare to happen but when it does it the person needs treatment immediately we're going to talk about those treatments a little bit later so what could cause this to happen well if a person already naturally has narrowed angles an anatomical defect that can cause it but medications can cause this that dilate that pupil because what it can do is it can push the lens or the iris forward and when you push that forward you close that angle and medication that can do that is like anticholinergics and you want to educate patients who are at risk for this to avoid those type of medications because you can get these like over the counter with like allergy medicines antihistamines or copd drugs or antidepressants so big risk with those now what are the signs and symptoms of this type of glaucoma well the patient is going to be able to notice them and they're not silent like with the other type of glaucoma so they can report severe eye pain they're going to have a lot of pain with this type of glaucoma they can also have nausea and vomiting they're going to have vision changes where their vision will be blurred from all that increased pressure when they look at lights they will see halos around the lights their eyes can be red the pressure can just be so high that it can cause edema on the cornea as you can see here in this picture and of course they're going to have very high iop now let's talk about the key concepts that you want to know about glaucoma as the nurse so to help us remember those key concepts we're going to remember the word thief so t is going to be about treatment goals and the treatment goal for the glaucoma of course is to reduce the intraocular pressure and this is going to help prevent damage to the optic nerve so medications are going to be the first line treatment for glaucoma most forms of medications are going to be in eye drops and patients can also receive oral meds and then surgical treatment can be provided and we're talking about like laser procedures or traditional eye surgery so first laser procedures a type of laser procedure that can be performed is called a selective laser trabeculoplasty also known as an slt and this procedure is relatively quick compared to the traditional eye surgery that we'll talk about next and it lowers the iop by using lasers to target certain parts of that drainage angle tissue which will cause changes to the tissue and these changes will allow that extra aqueous fluid to drain out of the eye and will decrease iop now a thing about this is that the iop will be lowered over several months and it's not a permanent solution next is a more traditional type of eye surgery and it's typically performed when they can't decrease intraocular pressure in the eyes because eye drops or other procedures are not working so a common type of traditional eye surgery is called a trabeculectomy and this is where some of the trabecular mesh work is removed and an opening is created to allow aqueous humor to collect in an area of the conjunctiva and this fluid will be reabsorbed and it will decrease iop now the patient whenever they have this procedure will have what's called a bleb and you can see that in this picture here we're pointing to the bleb in yellow and that is usually going to be found under the upper eyelid and this is where that fluid has collected now important thing to remember about these procedures is that vision that is lost already will not come back these procedures are going to help control pressure for several years and they are not permanent now let's talk about the post-op education for a patient who's had glaucoma surgery and things you need to know as the nurse so it's very important that you tell the patient that it's important that they go to all of their post-op appointments because here the doctor is going to be measuring their eye pressure and looking at other important post-op assessments also they don't need to be driving until they've been cleared by their doctor and if they have to go out in direct sunlight they need to wear protective sunglasses also they need to know how to instill eye drops which we're going to talk about a little bit later and to do it exactly as prescribed don't skip drops um do some here do some another day it needs to be exactly how the physician has ordered it because they're going to be taking antibiotics anti-inflammatories etc and to always use clean hands whenever they do this plus you need to tell the patient to refrain from rubbing their eyes because they may feel itchy after the procedure if they have stitches and they don't want to use their contact lenses and they want to avoid activities that increase eye pressure so you want to make sure that your patient isn't bending or doing straining activities like reading or even straining during a bowel movement because sometimes patients get constipated and they may need stool softeners during this time because we do not want them straining to get stool out because this increases their iop or lifting heavy objects furthermore you want to tell them that they need to wear their eye shield as prescribed and they may have blurred vision their eyes may tear up more frequently and their eyes may feel itchy this is normal after the procedure and this will decrease over time also they need to report any sudden vision loss or severe pain and some pain is common because they've just had surgery on their eye and it's very vital they monitor for infection like any abnormal discharge a fever extreme eye redness they can have some but any extreme or any extreme vision changes but again blurred vision at first is normal then we have h for helpful to remember the three s's of open angle glaucoma so you definitely want to know the differences between open angle and angle closure so the three s's for open angle is silent sight stopper so silent represents the patient's going to be asymptomatic until it's too late because the irreversible damage has been done to that optic nerve when the patient actually notices the loss of peripheral vision and they have that tunnel vision next is size so the vision loss can't be brought back and once blindness occurs it's permanent and why does it occur because we've had increased intraocular pressure that has damaged that optic nerve and then the last s stopper so the development of permanent vision loss blindness is stoppable hence it's avoidable if glaucoma is identified early through an eye exam that checks for eye pressure so let the patient know about this especially the patients who are at risk for glaucoma which we're going to talk about a little bit later and we can prevent the loss of vision through medications or procedures that help keep the iop low next is eye for immediate treatment for angle closure glaucoma so remember this is an emergency and this is not a type of glaucoma that's going to be silent with its signs and symptoms and medications can be used to lower that iop like eye drops or oral medications along with a surgical procedure like a laser iridotomy and this is where a small hole is created in the iris with a laser to drain that extra aqueous humor also a more traditional surgery could be an aerodyctomy and this is where they remove parts of the iris and remember the iris is that colored part of the eyes so look at those eyeballs it's the green part and this may be performed in both eyes because there is a risk of both of those eyes actually developing angle closure glaucoma so they can do that as a preventative measure next is e for eye drop so now we're going to talk about how to administer eye drops to a patient and i have a whole video a link should pop up in the corner where i actually demonstrate how to do this but i'm going to go over the highlights that you need to know and then we're going to go into the different types of medications so first you want to tell the patient that they don't want to skip days or abruptly stop taking the eye drops so some of these patients they have quite a few eye drops to take and they have to take them throughout the day so it can be hard getting into that routine and you want to stress to the patient that it's very very important that they take these eye drops exactly as prescribed because if they skip days and don't take them here or there they are ultimately risking losing their vision because these drops are made to help lower their iop also you want to stress the importance of always washing your hands before instilling eye drops because that is one of the big ways we get sick whenever we use our hands you know we're touching surfaces that have bacteria viruses in them if we touch our eyes with those hands we just transfer that virus or bacteria into our eye so always use clean hands when doing this next is about administering more than one type of eye drop medication so as a nurse this is important you know this and for the patient who's going to be instilling these at home so the rule of thumb is to space out each type of eye drop that the patient has to take about three to five minutes so let's say your patient has two eye drops they need to take so they'll take the one eye drop medication as prescribed and then they need to wait at least three to five minutes before instilling the other type of medication and why do we do this well we want that first medication to have time to work to be in the eye and if we quickly gave that second type of eye medication it would just wash out the first so you definitely want to have that time frame between the types of eye drops and then let's say your patient has an eye ointment ordered and an eye drop which one are you going to give first you will give the eye drops first and then you will give the eye ointment so whenever you give your patient those eye drops how do you instill them in the eye well you're going to place each drop on the lower sack of the eye and you can see this sack here in this picture on the right this is called the conjunctival sac you will not directly put the eye drop on the cornea via the eye now after instilling each eye drop medication you want to have the patient refrain from blinking but to keep the eye closed and to perform punctal occlusion so to do this you will have the patient or you use your index finger and gently place pressure at the side of the bridge of the nose over the lacrimal punctum and you can see that at the top pitcher that's an up close picture of it and you'll do this for about two to three minutes now why are we doing this well this is to prevent the medication you just gave them in their eye from draining down into the nasolacrimal duct and being absorbed by the blood which can cause widespread signs and symptoms so if you gave this patient a commonly prescribed glaucoma medication like a beta blocker or a cholinergic eye drop if we didn't perform this punctal occlusion that medication that's supposed to stay in the eye to do its job can drain down through this tear duct and can enter into the blood and actually cause those signs and symptoms of those medications and we don't want that to happen so now let's talk about those medications so how do medications work well they're going to help lower our iop and they're going to do it one of two ways or both ways they're going to decrease production of the aqueous humor and or they're going to increase the drainage of the aqueous humor so this is great we're going to get lower intraocular pressure so to help us remember some of these drugs because there's quite a few we're going to remember the abcs so that's going to help us remember four of them so first a for alpha agonist and these tend to end in i-d-i-n-e like brymotidine and these work with alpha receptors by activating them so we'll get the decrease of aqueous humor production because it constricts the ciliary body remember that producer aqueous humor and this helps increase the drainage of aqueous humor out of the eye and lowers our iop now remember this can cause systemic effects so we need to do punctal occlusion and one side effect that some patients can have is that they can feel very drowsy after taking this next is b for beta blockers and they end in o l o l like timolol and these decrease aqueous humor production and they can cause those systemic effects majorly so punctual occlusion very vital there's different types like cardio-selective and non-cardio-selective and they are not for patients with bradycardia asthma or copd and we talked in depth about this whenever we talked about our beta blocker video which you can access up here in the right corner if you want to watch that so with this you want to assess a patient's breathing and heart rate before administration then we have c for carbonic anhydrase inhibitors and they end in z-o-l-a-m-i-d-e so zolamides and they can be ordered orally or via drops and one medication type is called acetylzolamide and these decrease aqueous humor production so they're like diuretics that inhibit carbonic acid production now you want to assess the patient's allergies because if they have a sulfonamide allergy they cannot take these medications and then our last c is for cholinergics and these are meiotics and one type is pilocarpine and how this works is it helps lower the iop by constricting the pupil because that's what these drugs do and this will help increase the drainage of aqueous humor out through that trabecular meshwork now it's important to be familiar with the antidote for these drugs which is atropine and these drugs can cause that cholinergic effects like sweating increased elevation bronchospasm decreased heart rate and increase the eye sensitivity with light so they may have problems with vision and dim light and again it's very important that they perform punctual occlusion whenever they take this medication some other drugs include a prostaglandin analogues and they end in pros like bomatopose and these increase the drainage of aqueous humor out the eyes and they don't tend to cause as many systemic effects as those other medications that we just went over but an interesting side effect of this medication and depends on if you like this or not it can actually cause thicker and longer eyelashes and i have actually seen this in a patient it was an older patient and their eyelashes were the most beautiful eyelashes i've ever seen and i didn't think they were real and i looked in their history and they in fact were taking this medication for the treatment of glaucoma and another change that this medication can cause is that they can change the color of the iris to a brown color and then lastly we have rokinase inhibitors and these medications are relatively new for the treatment of glaucoma and a medication they have is called natarsadil and this increases the drainage of aqueous humor by inhibiting the rock pathway and this pathway is actually found in the trabecular mesh work so it will cause the mesh work to drain better because remember we talked about that this mesh work becomes stiff and it doesn't work very well so it'll start to drain and this will help decrease iop now one thing that this medication can cause because it causes dilation is that it can cause the eyes to become extremely red and then the last part of our mnemonic is f for factors that increase the development of glaucoma so to help us remember those risk factors remember the word save and we're talking about save your eyesight so s is for 60 or older especially if they have a family history a is for african american hispanic or asian community these people are at risk for glaucoma v for vascular problems such as like with diabetes hypertension and then e for elevated intraocular pressure because remember generally that normal iop was 10 to 21 millimeters of mercury so if they have these risk factors it's very important that they go for those eye exams so they can try to detect if the iop is elevated okay so that wraps up this review over glaucoma and don't forget to access that free quiz that will test you on this material